Alarm system.



C. F. MEAD & L. E. RICHMOND.

ALARM SYSTEM.

5 SHEETS-SHEET 1- Patented Mar. 26, 1918.

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ALARM SYSTEM.

APPLICATION FILED MM?- 7. I914.

1,260,930. Patented Mar. 26, 1918.

5 SHEETSSHEE 2.

0. F. MEAD & L. E. RICHMOND.

ALARM SYSTEM.

APPLICATION FILED MAR. 7.1914.

Patented Mar. 26, 1918.

5 SHEETS-SHEET 3- flesss 404W C. F. MEAD & L. E. RICHMOND.

ALARM SYSTEM.

APPLICATION FILED MAR-7.4914.

Patented Mar. 26, 1918.

5 SHEETS-SHED: 4.

c. F. MEAD & L. E. RICHMOND.

ALARM SYSTEM.

APPLICATION man MAR-7.1914;

1,260,930. Patented Mar. 26, 1918.

5 SHEETS-SHEET 5.

an" rare.

CARL F. MEAD AND LOUIS E. RICHMOND, QF CLEVELAND, OHIO, ASSIGNORS TO THE MEAD ELECTRIC SIGNAL COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

ALARM SYSTEM.

Specification of Letters Patent.

Patented Mar. 2c, 1918.

Application filed March 7, 1914. Serial No. 823,233.

To aZZcvhom it may concern:

Be it known that we, CARL F. MEAD and Louis E. RICHMOND, citizens of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Alarm Systems, of which the following is a specification.

This invention relates to signaling systems generally and particularly to that class known as fire alarm systems.

More specifically the invention relates to a system for use in buildings and the like and it comprises an alarm circuit connected to suitable bells, whistles or other signaling devices arranged at suitable points and controlled by a central station device having suitable commutator and indicator mechanism for giving the proper impulses to the alarm circuit to indicate the locality of the fire, this central station being operated by an electrical means which is normally in a closed circuit connectedto each floor or signal point and so arranged that upon the breaking of the circuit the proper signal is given.

The invention also contemplates the use of a suitable safe-guard such as a light over the central station connected in with the alarm circuit to normally indicate the proper condition of this circuit. Suitable mechanism for indicating the unset and unwound condition of the device and further mechanism whereby the different signaling devices at the different points in a building or factory may be actuated from or automatically in conjunction with a sprinklerhead or sprinkling system.

The invention may be further briefly summarized as consisting in the construction and combination of parts hereinafter set forth in the following description, drawings and claims.

Referring to the drawings, Figure 1 is a front elevation of thedevice; Fig. 2 is a. side elevation of a portion of the machine looking from left to right in Fig. 1; Fig. 3 is a side elevation looking from right to left in Fig. 1; Fig. 4 is a top plan view of the part shown'in Fig. 3; Fig. 5 is a sectional view through the device; Fig dis a bottom plan view; Fig. 7 is a bottom plan view of the clockwork mechanism; Fig. 8 is a section upon the line 88 of Fig. 7 looking in the direction of the arrows; Fig. 9 is a section upon the line 9-9 of Fig. 8; Fig. 10 is a detail view; Fig. 11 is a sectional view of a circuit. breaker adapted to be actuated by a flow of liquid in a stand pipe system for example; Fig. 12 isan end view thereof; Fig. 13 is an-elevation of a circuit breaker which may be used in "our device; Fig. 14: is a diagrammatic illustration of the apparatus; and Fig. 15is a detail view of a drop signal tobe utilized in conjunction with the device for notifying the fire department.

In carrying out. the invention any preferred form and arrangement of elements may be utilized, but we have shown one ar- Main central station apparatus.

The main central station apparatus comprises a supporting framework consisting ofinsulator strips 1 and 2 secured together by suitable cross strips 3 engaging a longitudinal strip 4 secured to each of the insulator strips 1 and 2. Secured to each of these longitudinal strips 4: is a U-shaped frame member 5 having mounted within the same a bearing block 6 of fiber or other insulating material. Each of these blocks is held in place by suitable screws 7 passing through the U-shaped frame member. Bo tatablv mounted in these two blocks is a commutator shaft 8 extending through both bearing blocks and between them it is provided with a commutator consisting of disks 9 having contact pins 10 secured between them, the number of contact nins between adjacent disks varying according to the number of signals to be given. This contact member, is held unon the shaft b suitable hubs .11- formed onthe first and last disk. andthese hubsareprovidedwith set screws 12. The lowermost disk, as shown in Fig. 2,

is engaged by a leaf contact 13 held in place by suitable screws 14, one of which may act as a binding post for one of the alarm circuit leads, as will later appear. The lower end of this shaft as shown in Fig. 3 is provided with a fiber face plate or disk 15 having a pair of diametrically disposed pin openings for receiving pins 16 for a purpose to be described. Supported in the bearing blocks 6 is a contact supporting rod 17, and this rodhas mounted upon it contact membore 18 each of which is provided with a fiber block 19 at the end and with an indi cator plate 21 projecting upward and adapted to be shifted from the position shown in full lines in Fig. 5 to the position shown in dotted lines in the same figure. Secured to each block 19 is a leaf contact piece 22 provided with a curved portion 23 adapted for engagement with the contact pins 10 and with an upwardly extending portion adapted to normally assume the full line position shown in Fig. 5, but upon the clockwise movement of the corresponding contact member 18 to be shifted over into the dotted line position and engage a contact strip 24 extending throughout the group of contact pieces 22 and secured in place by short strips 25 in turn secured to a longitudinally disposed guiding strip 26 secured to the outer faces of the U-shaped frame members, as is clearly shown in Fig. 3. This contact strip 24; is provided with a suitable binding post 27 connected to the other lead of the alarm circuit, as will later appear. The normal tendency of the contact members 18 is to move down and bring their contact pieces into engagement with the contact pins, and this is brought about by a plurality of springs extendings between the indicator arms 20 and a spring strip 28 mounted upon the supports 29 secured to the top of the U shaped frame members.

Secured in the end of each of the contact members 18 is a tri rod 30, and these trip rods extend bey'onc the U-shaped frame members 5 and through suitable guiding mechanism which consists of the guide strips 26 and a guide strip 31, each of which is provided with a guideway 32 and these guideways receive a locking plate .33 pro- I vided with a plurality of trip slots, one for figure 7. When the contact members are in 'each rod. Each of these slots consists of a longitudinally disposed portion 34 and a diagonally disposed portion 35, the two portions merging at one end of the longitudinal portion and forming 111 its entirety a the full line position shown in Fig. 5, they are in alinement with the longitudinally disposed slot portions 34, and when-any one of the contact members is moved into the dotted line'position, shown in Fig. 5, thewall at the edge 'ofthe diagonal portion '35 is engaged and the locking plate 33 is moved upward, causing the trip rods of the remaining contact members to move into the longitudinal portion 34 of the slot, and hence locking them against movement.

From the description of the parts already described, it will be seen that the normal tendency of the contact members is to move down and shift the locking plate 33 so as to bring the contact pieces into engagement with the contact, and this tendency is overcome by a plurality of electrical devices, one for each contact member. This mechanism will now be described.

Secured to the longitudinal strips 4 and to the left of the mechanism already described is a plurality of magnetic devices, and each consists of a supporting portion 36 secured to longitudinal magnet strips 3'? in turn mounted upon the longitudinal strips 4. Each of the supporting portions has integral with it an outwardly extending bearing arm 38 carrying a pivot pin 39 upon which is mounted an armature and trip lever 40 extendin r under the corresponding trip rod 30 of the corresponding contact member, and. a rearwardly extending armature portion 41 provided with a thin non-metallic core engaging plate 42 on the underside. Cooperating with this armature portion 41 is an electromagnet comprising a core d3'and a coil 4.4 held in place upon the supporting portion 36, as by securing the core in such portion. When the armature portion ll is in engagement with the core there is a complete magnetic circuitformed between the two ends of the poles, through the supporting portion, the outwardly extending arm andthe armature.

Each of the electro-magnets is provided with a square insulating head 15, and to these heads are secured suitable connection plates 46 of insulating material. Mounted upon the outer face of each of these plates is a long connection strip 47 which is 0011- nected at one end to one of the leads from the corresponding magnet and at the other end to a bus bar -18 extending across the several plates 16 and connected to the similar strips 47 ofthe other magnets. The other lead from each magnet is brought out to a short connection strip d9 provided with a binding screw 50. The bus bar 48 is held in place and is connected with the several connecting strips 47 by suitable screws 51 any one of which may be used as a binding post for one of the circuit breaker leads.

From the description already given, it will be seen that when the magnets are energized will'be held with their ends 23 out of engagement with the contact pins 10.- 'Upon the breaking of the circuit through any one or more of the magnets, however, the corresponding armatures will be released and the corresponding contact members will move into the dotted line position shown in Fig. 5, with the contact in the'path of the pins, this movement causing the shiftingof the locking plate and the locking of the remaining trip rods as has already been described. At the same time that the shifting of any of the contact members takes place, the corresponding indicator will be brought into indicating position to indicate the particular signal which has beengiven;

Resetting device.

. Suitable mechanism is provided for resetting the several trip levers 4C0, and it consists of a shaft 52 extending the full length of the mechanism already described and to a distance below the same for a purpose which will later appear. This shaft is supported in a pair of brackets 53 and 54: secured to the arms 38 of the upper and lower magnets, and it has rigidly secured to it a pair of arms 55 and 56,-the ends of which receive a rod 57 extending under all of the trip levers 40, as is shown in Figs. 1 and 5. The arrangement of this device is such that when it is moved so as to bring the rod 57 up against the underside of any one or more of the trip levers which have been operated, the further operation of the rod will cause such devices to be brought up until their .armatures are in the range of their magnets, and if the circuits be closed in the magnets, then the trip levers will be held in place.

Oommutator operating mechanism.

The means employed for-driving the commutator mechanism and operating such other parts of the device as are anipulated mechanically may be in the form of any suitable device for furnishing motive power, but we preferably employ a spring motor, and this device will now the described.

Secured to the framework of the machine is a spring motor comprising side frame members 58 and 59. held together by suitable braces 60 spaced at convenient points between these members. These plates are provided with suitable openings forming bearings for a main spring shaft 60- which projects beyond the frame and is there provided with a disk 61, as shown in Fig. 7 having thereon a crank pin 62' The projected end of the shaft and the crank pin serve as a means for receiving a suitable key for winding. This shaft between the frame members 58 and 59 isprovided with a. main spring 63 and a main gear 64: 0peratively connected withthe shaft 60 by the usual. ratchet andpawl mechanism common in spring motors and like structures. This main driving gear 64 meshes with a pinion 65 .mounted upon a shaft 66 and rigidly connected to an intermediate gear 67 meshing with a pinion68 mounted upon another intermediate shaft 69 carrying another intermediate gear 70. This intermediate gear meshes with a pinion 71 mounted upon the governor shaft- 72. This governor shaft is provided with a suitable governor of any preferred type and operating in any preferred manner. The governor in the present form, however, is provided with suitable centrifugal arms 73. This shaft 72 is also provided with a brake wheel 74.. Cooperating with the brake wheel is a brake head 75 mounted upon a rod 76 secured in a boss 77 mounted upon a shaft 78. This shaft 78 is mounted between the frame plates 58 and 59 and extends above the upper plate, as shown in Figs. 1 and 10, and is there provided with a lever 79 having an inclined face 80 adapted to be engaged by a screw '81 adjustably mounted in an extension 82 of the locking plate 33. This extension is clearly shown in Fig. 3. A suitable spring 83 tends to draw this lever 79 into a position to cause the brake head 75 to engage the periphery of the brake wheel and when the extension 82 is down in the position shown in Fig. 3, the screw 81 is down in the position shown in Fig. 10, and the brake is engaging the brake wheel 74 and the spring motor is at a state of rest. ing plate 33 is raised upward, the end of the screw 81 shifts the lever 79 in a direction to move the brake head 7 5 from the pe riphery of the brake wheel, releasing the spring motor. The intermediate shaft 66 is provided with a driving disk 84: having mounted therein the pins 16 engaging in the openings in the disk 15 mounted on the commutator shaft 8. In order to limit the winding and unwinding of the motor we provide on the lower face thereof an arm 85 pivoted upon a pin 86 secured to the plate 59, and it has an enlarged end plate portion 87 provided with an arc -shapcd slot 88 therein. for receiving a pin 89 mounted upon abracket 90 secured by a screw 91 to the plate 59. This pin 89 serves as a guide for 5118373111 85. The extreme outer edge of this plate portion 87 is concentric with the pin 86 and is provided with a plurality of notches 92, and these notches are uniformly spaced and are adapted to be engaged successively by the pin 62 on thedisk 61 as it rotates with the spring shaft 60 of the motor, and the arrangement is such that as the motor operates, the pin 62 engages in the notches and gives the plate portion 87 a counterclockwise movement, as shown in Fig. 7 and a'clockwise movement as shown in Fig. 9. The underside of this plate portion 87, as shown in Fig. 7, is provided with a pair of When the lockpins 93 and 94 and they are adapted to-engage a stop lever 95 mounted upon a pin or bolt 96 secured in the plate 59. The opposite end of this lever is provided with a projection 97 adapted to be moved in the path of a stop 98 secured to the intermediate gear 67, as shown in Figs. 1, 7, 8 and 9, when the plate portion 87 is in the position shownin Figs. 7 and 8. When the'plate portion is in the position shown in Fig. 6, however, the pin 93 engages the lever and shifts it so that the projection 97 is out of the path of the stop 98 on the gear wheel 67 so that the clock is free to run if the brake is off.

Resetting signal.

In order to indicate the condition of the machine and to indicate thecondition of'the motor, that is as to whether it has been wound or not, the system includes a buzzer or other signal which is supplied with current from any suitable source, and is actuated by both the reset lever shaft and the spring motor in such a manner that when the shaft 52 has been operated by the giving-of an alarm signal and when the spring motor has started to operate, this buzzer is started and will continue to operate until both the reset lever has been actuated and the clock has been wound. and the operation of a single one of these devices without the other will not silence this device, and it is arranged in the following manner.

Secured to the lower plate 59 of the spring motor is an insulating block 99 carrying a leaf contact strip 100 on one side and a leaf contact strip 101 on the opposite side. The leaf contact strip 100 has a contact portion 102 at one end extending in one direction,

and a leaf contact portion 103 extending in the opposite direction. The former, contact portion 102, cooperates with an extension 104- of the contact member 101 and extends into the path of a pin 105 mounted upon an insulating block 106 secured to the plate portion 87 and it is so located that when the motor is completely wound the pin breaks contact between the portions 102 and 10 1. As soon a the plate portion 87 moves however as with the unwinding of the motor, these two contact portions come into engagement and a circuit is established through the buzzer. The contact strip 101 is also pro vided with a contact portion 107 extending along in parallelism with the portion 103, and these are adapted to be brought into engagement by a projection 108 carried by a lever 109 secured to the reset shaft 52. When one of the trip levers 10 has operated, and the rod 57 has caused the rocking of the shaft 52 through the arms 55, this lever 109 causes the projection 108, which is a screw in this case, to engage the contact portion 103 and bring it into engagement with the contact portion 107, with the result that the circuit through the alarm' is closed at this point, and the only Way to break the circuit at this point is by shifting the shaft 52 to reset the trip lever 40 which has been operated or in other words, when the machine is reset to sto any signal given in the manner described t 118 circuit established at the point of contact of the contact portions 103 and 107 is broken.

Switch mechanism for indicator and control for alarm circuit.

This mechanism consists of a lever 110 of fiber orother insulating material having in its two ends contact rods 111 and 112, the former engaging between two leaf contacts 118 and 114, and the latter engaging between leaf contacts 115 and 116, all of said contacts being mounted upon and insulated from each other by a fiber block 117 secured to the framework. The connection of these parts in the circuit will be described later.

Circ it hrcalccr.

this position onto a button 122 breaks. the

circuit and causes the operation of the magnet to which it is connected.

Sprinkler system contact mechanism.

It is desirable in many instances in case of operation of the sprinkler system to have an alarm sounded indicating the locality of the operation of the system, and w have shown in Figs. 11 and 12 views of one of a series of valve circuit breaker devices which are placed in a sprinkler line at various points and are connected with the electric circuit leading from this locality to the alarm system and preferably connected in series with the circuit breaker of this locality. Each of these devices consists of a valve casing 123 arranged in the sprinkler system pipe 124 and provided internally with a valve seat 125 inclined as shown and adapted to cooperate with a flat valve 126 provided with a square opening for receiving the square shank 127 of a valve stem 128 which extends through a suitable stufiing box 129 to the outside of the casing. This valve stem outside of the casing is provided with a crank arm 130 carrying an insulating block 131 provided with an upwardly extending'leaf contact 132 adapted to engage a contact screw 138 mounted upon an insulating block 134 secured to an car 135 carried by the casing, when the valve 126 is seated. One of the lines leading to or from the circuit breaker is broken and two endsconnected to this device, one to theleaf con tact 132 and the other to the contact screw 133s0 that when the flow through the casing lifts the valve 126 the circuit is broken and the alarm apparatus'is set in motion.

Diagrammatic illustration of the. system.

The System comprises several elements and for clearness these elements and their circuits will be separately described,referring to the diagrammatic view in Fig. 14.

7 Alarm and its circuit;

The alarm comprises preferably one or more bells 136 only one being shown in the drawings. Each bell is connected by a line 137 with one side of the alarm battery 138 located at any suitable point. The other side of this alarm circuit is provided with two branches 139 and 140, the former leading to the contact 114 of the switch mechanism for indicating and controlling the alarm circuit, and the latter leading to the contact 115 of the same mechanism, this latter line 140 being utilized for indicator purposes, as will later appear. The contact 113 opposed to the contact 114 is connected by a line 141 with the bus bar 24 of the commutator mechanism already described while the leaf contact 13 0f the commutator mechanism is connected by a wire 142 to the opposite side of the battery 138 sothat when the contact rod 111 engages the two contacts 113 and 114 and one of the contact pieces is in the proper position, the circuit through the alarm is completed and it will be sounded in an obvious manner.

' ludicator for alarm circuit.

normal rest position of the apparatus-being such that the rod 112 is in engagement with these two contacts.

Actuaziug circuit.

The actuating circuit connected with the battery'138 and it comprisesa line 146 connected to the bus bar 48 in turn connected as already described With each of theactuating magnets of the commutator mechanism. The opposite side of the battery 138 in the actuating circuit is then connected by a line 147 with the pivot bolt 119 of each manually operated circuit breaker or with the contact screw 133 or" each sprinkler system valve operated circuit breaker, the opposite side of the sprinkler system valve operated circuit breaker being connected by a wire 148 with the pivot bolt 119 of the manually operated circuit breaker, the active contact 121 of each manuallyoperated circuit breaker being connected by a separate line, as for example, the line 149 with its corresponding magnet 44. By this connection it will be seen that by providing a sprinkler operated circuit breaker and a manually operated circuit breaker in series in each locality that the actuation of either one will cause the operation of the particular portion of the commutator mechanism for indicating that particular locality. It will also be seen that when a manually operated circuit breaker is actuated, or in other words is shifted to the button 122, the commutatormechanism may not be reset until this device is restored by reason of the fact that the circuit through the electro-magnet which has been actuated by this particular line or circuit, will not be energized and will not hold its lever 40 .in position.

Resetting signal circuit.

This circuit comprises a separate battery 150 connected by a wire 151 with one side of a buzzer or other similar indicator 152, the opposite side of this buzzer being connected by a line 153 with the leaf contact strip having the contact portions 102 and 103 arranged upon the motor. The opposite side of the battery 150 is then connected by aline 154 with the opposite leaf contact strip having contact portions 104 and 107. By means of this arrangement. it will be seen that upon the actuation of the device and the rocking of the shaft 52 the contacts 103 and 107 will be brought into engagement, and the buzzer or signal 152 will be spoken and after the motor has operated suiiiciently to move thearm 85 upward as shown in Fig. 14, the contact 104 will be brought into engagement with the contact 102 and the circuit will be completed at this point through the buzzer so that in resetting even if the trip levers 40 have been brought back to reset position the buzzer or signal 152 will not cease speaking until the motor is rewound, or in the event that the motor should be rewound the buzzer or signal 152 will continue to operate until the trip levers have been reset. In this way the device is safeguarded.

Signal to fire department.

,The system may be provided with suit able means for notifying the fire department,

and it comprises the device set forth in Figs. 1 1 and 15 comprising an electro-magnet 155 mounted upon a suitable supporting bracket and armor member 156 carrying suitable ears 157 having pivoted therein an armature member 158 carrying a trip 159 provided with a hook 160 adapted to engage a non-magnetic drop 161 provided with a suitable signal 162. The magnet 155 is connected by a wire 163 with the contact 113 and by a wire 16% with the line 137, so that upon the closing of the circuit between the contacts 113 and 114 this drop will be actuated and the signal given.

It is obvious that Where the system is to be installed in plants or buildings covering a large area and where there would be too great a drop in the circuits suitable rclays may be provided in these circuits in a Well known manner to bring about the proper operation of the device. It is also possible to have the commutator mechanism operated on a low voltage and the alarm circuit to operate on high voltage by the use of relays.

Having described our claim 1. In an alarm system, an alarm circuit, alarm devices in said circuit, commutator mechanism for controlling the alarm circuit,

invention, We

electrical controlling means for said commutator mechanism adapted upon a closed circuit through the controlling means to hold the commutator inoperative, actuating means for said controlling means and comprising a circuit breaker having open and closed positions, and resetting mechanism inoperative when the circuit breaker is in open position.

2. In an alarm system, an alarm circuit, alarm devices connected in said circuit, commutator mechanism for said alarm circuit and comprising a commutator member, contact devices cooperating with said contact member one for each signal, electro-magnetic means controlling the operation of said contact pieces, said electro-magnetic devices being adapted to hold said contacts normally out of engagement with the commutator member, and actuating mechanism comprising a normally closed circuit breaker, and a circuit leading to each electromagnetic controlling device, the circuit breaking means of each locality being independently oper able with its electro-magnetic controlling means.

3. In an alarm system, an alarm circuit, alarm devices connected in said circuit, commutator mechanism for said alarm circuit and comprising a commutator having a plurality of sections one for each signal, and contact pieces one for each section, means normally tending to shift said contact pieces intoengagement with the commutator, electro-magnetic means adapted upon a closed circuit therethrough to hold said contact pieces against their normal tendency and out of engagement, and actuating mechanism for said electro-magnetic means and comprising a circuit breaker for each locality, and an independent circuit leading to the corresponding electro-magnetic means.

41-. In an alarm system, an alarm circuit, alarm devices connected in said circuit, commutator mechanism for said alarm circuit and comprising a commutator having a plurality of sections one for each signal, and contact pieces one for each section, means normally tending to shift saidcontact pieces into engagement withthe commutator, trips for controlling said members one for each contact member and each including an armature, an electro-magnet cooperating with each armature, a circuit breaking means for each magnet, and a separate circuit between each circuit breaking means and its magnet, said circuit being normally closed when the alarm is inactive.

5. In an alarm system, an alarm circuit. alarm devices connected in said circuit, commutator mechanism for said alarm circuit and comprising a commutator member, contact devices cooperating with said contact member one for each signal, electro-magnetic means controlling the operation of said; contact pieces, said electro-magnetic devices, being adapted to hold said contacts normally out of engagement with the commutator member, actuating mechanism comprising a normally closed circuit breaker, and, a circuit leading to each electro-magnetic con trolling device, the circuit breaking means of each locality being independently operable with its electro-magnetic controllingmeans, and an independent signaladapted to be set in operation with the giving of an alarm signal and to continue in operation until the deviceis set.

6. In an alarm system, an alarm circuit, alarm devices connecting said circuit, comimitator mechanism for said alarm circuit and comprising a commutator having a pluality of sections one for each signal, and contact pieces one for each section, means normally tending to shift said contact pieces into engagement with the commutator, trips tor controlling said members, one for each contact member and each including an armature, an elcctro-magnet cooperating with each armature, an independent circuit for each electro-magnet, and a circuit breaking device for said circuit operated by the actuation of a sprinkler system. i

'7. In an alarm system, an alarm circuit. alarm devices in said circuit, commutator mechanism for controlling the alarm circuit, electrically controlled means for said commutator mechanism adapted upon a closed circuit through the controlling means to hold the commutator inoperative, several actuating means for said controlling means and each comprising a circuit breaker and an. electrical circuitthcretor, a switchdevice in said alarm circuit operated by. said controlling means,means for indicating the operative condition of. the alarm circuit when the system is'idle, and means operat ing conjointly with said switch device for disconnecting said indicating means when the alarm device is operated.

8 Inan alarm system, an alarm circuit, alarm devices in said circuit, commutator mechanism for controlling the alarm circuit, electrically controlled meansfor said commutator mechanism adapted upon a closed circuit through the controlling means to hold the commutator inoperative, several actuating means for said controlling means and each comprising a circuit breaker and an electrical circuit therefor, means indicating the condition of the alarm circuit when the system is idle, and means for disconnecting the indicating means when the alarm device is operated.

9. In an alarm system, an alarm circuit, alarm devices in said circuit, commutator mechanism for controlling the alarm circuit, electrically controlled means for said commutator mechanism adapted upon a closed circuit through the controlling means to hold thecommutator inoperative, several actuating means for said controlling means and 7 each comprising a circuitvbreaker and an electrical circuit therefor, means indicating the condition of the alarm circuit when the system is idle, means for disconnecting the indicating means when the alarm device is operated, means for resetting said actuating means when operated, and means operated by said resetting means for restoring said indicating means to operative condition.

10. In an alarm system, an alarm circuit, alarm devices in said circuit, commutator mechanism for controlling the alarm circuit, electrically controlled means for said commutator mechanism and adapted upon a closed circuit through the controlling means to hold the commutator inoperative, several actuating means for said controlling means and each comprising a circuit breaker and an electrical circuit therefor, and means for indicating the operative condition of the alarm circuit when the system is idle, said indicating means comprising an indicator, an electric circuit, and suitable switch mechanism actuated by the commutator mech anism for closing the circuit through the indicator when the mechanism is idle and rendered inoperative with respect to the alarm circuit when the alarm is given.

11. In an alarm system, an alarm circuit, alarm devices in said circuit, commutator mechanism for controlling the alarm circuit,

electrically controlled means for said co1n.

mutator mechanism and adapted upon a closed circuit through the controlling means to hold the commutator inoperative, several actuating means for said controlling means and each comprising a circuit breaker and an electrical circuit therefor, and means for automatically indicating the operative condition of the alarm circuit when the system is idle, said indicating means comprising an indicator, an electrical circuit for actuating the same when the mechanism is idle, and means for rendering said circuit inoperative upon actuation of the alarm device.

12. An alarm system comprising an alarm circuit, alarm devices in said circuit, a central station comprising suitable contacts and commutator mechanism, means for actuating said parts to give several signals, means for indicating the unset condition of the parts after actuation, and means for automatically indicating the operative condition of the alarm circuit when the device is idle, and means for rendering said last named indicat ing means inoperative when the alarm device is operated.

13. A central station for alarm systems comprising a commutator member having a section for each signal, a plurality of contact devices, one for each commutator section, means normally tending to throw said contact devices into engagement with the commutator, suitable trips for holding said contacts against such movement and each including an armature, a plurality of electromagnets one for each trip, and adapted to hold said trips in position to prevent the normal tendency of the contacts upon a closed circuit through the magnet.

14:. A central station for alarm systems comprising a commutator member having a plurality of sections, one for each signal, a plurality of contact members, one for each signal, a contact carried by each contact member, a trip lever for each contact mem her, an armature for each trip lever, an electro-magnet for each armature, said parts being arranged such that the closing of the circuit, through the magnets Will hold the trips in position to prevent the normal tendency of the contact members, and means for resetting the trip levers after actuation and comprising a shaft, a pair of arms carried by said shaft, and a rod extending under said trip levers and adapted to move the same into set position.

15. A central station for alarm systems comprising a commutator member having a plurality of sections, one for each signal, a plurality of contact members, one for each signal, a contact carried by each contact member, a trip lever for each contact member, an armature for each trip lever, an electro-magnet for each armature, said parts being arranged such that the closing of the circuit through the magnets will hold the trips in position to prevent the normal tendency tion indicator cooperating with said switch 10 when in one position.

In testimony whereof we affix our signatures in presence of two witnesses as follows:

CARL. F. MEAD LOUIS E. RICHMOND.

adapted to cooperate with one part of said Witnesses: switch when in one position, another pair of G. O. FAn UHARsoN, contacts connected to an alarm circuit condi- C. H. TRESCI-I.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Iatents, Washington, D. G. 

